Over a six-month period, a teacher's aide at a Palm Beach County charter school repeatedly sexually assaulted a 15-year-old girl he met at church, according to a Palm Beach County Sheriff's Office arrest report.

He threatened to tell her parents and church leaders about her behavior — and send them nude pictures of her — if she refused him, the report states.

Hugh Murray, 28, of Lake Worth, was arrested Thursday on multiple charges, including sexual assault, extortion, battery and lewd or lascivious behavior. He remained in the Palm Beach County Jail late Friday in lieu of $510,000 bail.

For the last two years, Murray worked as an aide at the Palm Beach County School for Autism, a Lake Worth charter school. After learning of the charges against Murray from the Sun Sentinel, school executive director Ann Levene-Eisenberg said he's fired.

"He's done. Done. Gone. Out," she said Friday. "He's dismissed immediately. He is not to ever return to our campus. Ever."

Levene-Eisenberg said school policy bars employees from ever being alone with a child and background checks are required. The children's safety is the school's first priority, she said.

The victim, now 16, called police on Monday after telling her mother that Murray had grabbed and harassed her, according to the report. She met the man, who according to the arrest report is a Jehovah's Witness, at a church event when he was 27.

After taking the report, deputies told Murray not to contact the girl. He continued trying, the arrest report states. Monday night, he sent her an email telling her to "call ASAP or it will be released to your parents. Everything will come out."

As investigators listened on the line, he repeated that threat to her during a phone call and said he'd post the nude pictures of her online. Murray told the girl police involvement didn't concern him.

The two met in July 2012 and developed a friendship, according to the report. It became sexual in December, when Murray touched the then 15-year-old and assaulted her despite her pleas for him to stop.

Two times this month, Murray showed up at the girl's house unannounced after his attempts to reach her failed. Both times, he tried to talk her into sex, once by saying he "couldn't think straight" without it, according to the report. She tried to refuse his advances and threw up after the assault.

The second time, he grabbed her by her arms and threatened to talk to her parents about her behavior if she refused him, according to the report.

After the victim reported Murray to the Sheriff's Office, he sent her a message using the name "John Smith," saying he would send letters about her behavior to her parents and elders at their church if she didn't talk to him.

"I don't want to do what I'm going to do but I feel like I have no choice unless u say something," the text message read. "I'm sorry but they will get a letter along w/pics and txts to prove what I'm saying."

With investigators listening on the line, the victim called Murray's cellphone. Murray said she had no right to go to the police and that she "really screwed up" by doing so, according to the report.

He said he took a risk by being with her because he could go to jail and that they were both responsible for what happened. He said he was sorry for the pain he caused her, the report states, and repeated the threat to tell her family and church leaders.

"You feel the way you do and you did what you did," Murray said. "So, if I was you, I would get things in order ... once I come and tell them, this is going to change a lot of things for you."

Levene-Eisenberg, the school director, said she was shocked by the allegations against Murray. He had been an "amazing" aide, she said.